Methods of manufacturing printed circuit board (PCB) contain a subtractive method and a semi-additive method, etc. However, the subtractive method pollutes environment and increases production cost. As using the semi-additive method, cooper is etched decreasingly in deposition process.
As using the subtractive method to manufacture a printed circuit board which includes a copper clad laminate (CCL), and the CCL has a polymer substrate, a glass fiber, and a copper foil, wherein the copper foil is fixed on the polymer substrate and a main part of the copper foil is etched or eliminated. However, water consumption increases greatly as etching the copper foil in photolithography process and in rinsing process. Furthermore, chemical waste and heavy metals produce and pollute the environment.
As applying the semi-additive method to manufacture the printed circuit board, a copper layer is plated on the substrate in chemical deposition process (i.e., electroless deposition), and photoresist (PR) is fixed to expose circuit pattern, then the copper layer is plated on the circuit pattern. Thereafter, the PR is removed and the circuit pattern is etched so as to eliminate a part of the copper layer on the non-circuit pattern. However, copper consumption increases.
A photosintering method is disclosed in U.S. Publication No. 2015/0147486 A1 and U.S. 2008/0286488 A1 so as to manufacture metal pattern on the printed circuit board.
A laser method is disclosed in US Publication No. 2014/0120453 and is employed to manufacture micro-super capacitor. Laser induced graphene (LIG) materials and their use in electronic devices is disclosed in WO 2015175060 A3, but electric conductivity of the LIG is not high.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.